[management,client] Default to NetBird's upload service when nothing is configured

The previous commit made a peer with no destination — no MDM override, no URL
named by the caller, nothing published by its management server — refuse to
upload and keep the bundle local unless it was enrolled with NetBird's cloud.
That closed the reported data-boundary concern, but it broke the default for
everyone who uploads a bundle as part of their day: a self-hosted user opening
a support ticket got a refusal where the command used to work.

Product decision (NetBird's, not the reporter's): the knob to keep bundles
inside your own infrastructure is what this branch provides, and it is enough.
The default stays the service NetBird runs, self-hosted included. An admin who
needs the bundles to stay in-house configures the destination; until then the
everyday flow keeps working.

So ResolveUploadURL drops the cloud check, the sentinel error and the
managementURL argument, and never fails:

    MDM  >  explicitly named URL  >  published by management  >  NetBird's service

Nothing observable changes for a deployment that configures nothing, which also
removes two edge cases the fail-closed default had: a peer still enrolled on the
legacy api.wiretrustee.com host would have been classified self-hosted and
refused, and an upgrade would have silently stopped uploads for self-hosted
deployments relying on them. The privilege gate is unaffected — a host other
than the default one still requires a privileged caller, so pointing the CLI
somewhere other than what management published needs root.

client/internal/debug/destination.go

@@ -1,41 +1,29 @@
 package debug
 
 import (
-	"errors"
-
-	"github.com/netbirdio/netbird/client/internal/metrics"
 	"github.com/netbirdio/netbird/upload-server/types"
 )
 
-// ErrNoUploadDestination reports that a bundle has nowhere to go: the
-// management server of this deployment publishes no upload service, and the
-// peer is not enrolled with NetBird's cloud either. A debug bundle carries the
-// peer's logs, routes, DNS and firewall state, so the default is to keep it
-// inside the operator's control sphere rather than fall back to the service
-// NetBird runs.
-var ErrNoUploadDestination = errors.New("this deployment publishes no debug bundle upload service; set it on the account settings or in the management server config, or pass an explicit upload URL")
-
-// ResolveUploadURL decides where a debug bundle may be uploaded.
+// ResolveUploadURL decides where a debug bundle is uploaded.
 //
-// requested is a destination a caller named explicitly (a CLI flag, the daemon
-// request); it always wins, and the callers that accept one gate it separately.
-// published is what the management server of this deployment advertises, which
-// the engine holds (Engine.DebugUploadURL). With neither, only a peer enrolled
-// with NetBird's cloud falls back to the service NetBird runs — for anyone else
-// that would carry the bundle out of the deployment the operator controls, so it
-// fails closed with ErrNoUploadDestination.
-func ResolveUploadURL(requested, published, managementURL string) (string, error) {
+// requested is a destination a caller named explicitly — an MDM override, the
+// CLI's --upload-bundle-url, a remote job's upload_url; it always wins, and the
+// callers that accept one gate it separately (see requirePrivilegeForUploadURL:
+// any host other than the default needs a privileged caller). published is what
+// the management server of this deployment advertises, which the engine holds
+// (Engine.DebugUploadURL). With neither, the upload service NetBird runs is the
+// default, for a self-hosted deployment as much as for a cloud one: an operator
+// who needs the bundles to stay inside their own infrastructure points either
+// knob at their own upload service, and until they do the everyday
+// "collect a bundle and send it to support" flow keeps working.
+func ResolveUploadURL(requested, published string) string {
 	if requested != "" {
-		return requested, nil
+		return requested
 	}
 
 	if published != "" {
-		return published, nil
+		return published
 	}
 
-	if metrics.DetermineDeploymentType(managementURL) == metrics.DeploymentTypeCloud {
-		return types.DefaultBundleURL, nil
-	}
-
-	return "", ErrNoUploadDestination
+	return types.DefaultBundleURL
 }

client/internal/debug/destination_test.go

@@ -4,83 +4,50 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 
 	"github.com/netbirdio/netbird/upload-server/types"
 )
 
 func TestResolveUploadURL(t *testing.T) {
 	const (
-		cloudMgm      = "https://api.netbird.io:443"
-		selfHostedMgm = "https://netbird.example.com:33073"
-		operatorURL   = "https://upload.example.com/upload-url"
-		requestedURL  = "https://requested.example.com/upload-url"
+		operatorURL  = "https://upload.example.com/upload-url"
+		requestedURL = "https://requested.example.com/upload-url"
 	)
 
 	tests := []struct {
-		name          string
-		requested     string
-		published     string
-		managementURL string
-		want          string
-		wantErr       bool
+		name      string
+		requested string
+		published string
+		want      string
 	}{
 		{
-			name:          "requested wins over published",
-			requested:     requestedURL,
-			published:     operatorURL,
-			managementURL: selfHostedMgm,
-			want:          requestedURL,
+			name:      "requested wins over published",
+			requested: requestedURL,
+			published: operatorURL,
+			want:      requestedURL,
 		},
 		{
-			name:          "requested wins on cloud too",
-			requested:     requestedURL,
-			managementURL: cloudMgm,
-			want:          requestedURL,
+			name:      "requested wins with nothing published",
+			requested: requestedURL,
+			want:      requestedURL,
 		},
 		{
-			name:          "published used when nothing requested",
-			published:     operatorURL,
-			managementURL: selfHostedMgm,
-			want:          operatorURL,
+			name:      "published used when nothing requested",
+			published: operatorURL,
+			want:      operatorURL,
 		},
 		{
-			// A cloud deployment publishing its own destination must not be
-			// overridden by the compiled-in default.
-			name:          "published wins over the cloud fallback",
-			published:     operatorURL,
-			managementURL: cloudMgm,
-			want:          operatorURL,
-		},
-		{
-			name:          "cloud falls back to the NetBird service",
-			managementURL: cloudMgm,
-			want:          types.DefaultBundleURL,
-		},
-		{
-			// The whole point of GHSA-hf99-43rj-h577: no silent hop to a
-			// vendor-controlled destination.
-			name:          "self-hosted with no destination fails closed",
-			managementURL: selfHostedMgm,
-			wantErr:       true,
-		},
-		{
-			name:          "unknown management URL fails closed",
-			managementURL: "",
-			wantErr:       true,
+			// The default stays the service NetBird runs whatever the
+			// deployment: an operator who wants the bundles elsewhere says so,
+			// and until then collecting one and sending it to support works.
+			name: "nothing configured falls back to the NetBird service",
+			want: types.DefaultBundleURL,
 		},
 	}
 
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
-			got, err := ResolveUploadURL(tc.requested, tc.published, tc.managementURL)
-			if tc.wantErr {
-				require.ErrorIs(t, err, ErrNoUploadDestination)
-				assert.Empty(t, got)
-				return
-			}
-			require.NoError(t, err)
-			assert.Equal(t, tc.want, got)
+			assert.Equal(t, tc.want, ResolveUploadURL(tc.requested, tc.published))
 		})
 	}
 }